发明名称 |
Spacecraft TDMA communications system with synchronization by spread spectrum overlay channel |
摘要 |
In a time division multiple access spacecraft communication system, each ground station determines when to send its information packets to arrive at the spacecraft at the beginning of a time slot. The calculation is based upon knowledge of the locations of the spacecraft and the transmitting ground station. A master ground station determines the location of the spacecraft by the use of the propagation delays between the various ground stations (including itself) and the spacecraft, together with knowledge of the locations of the ground stations. The spacecraft location is then transmitted back to the various ground stations. The determination of propagation delay by each ground station is performed by repeatedly transmitting a ranging signal containing a multiple-bit unique word to the spacecraft, and counting spreading code chips until the next unique word is received from the spacecraft.
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申请公布号 |
US5878034(A) |
申请公布日期 |
1999.03.02 |
申请号 |
US19960655112 |
申请日期 |
1996.05.29 |
申请人 |
LOCKHEED MARTIN CORPORATION |
发明人 |
HERSHEY, JOHN ERIK;HLADIK, STEPHEN MICHAEL;SAULNIER, GARY JUDE |
分类号 |
G01S19/05;G01S19/11;G01S19/21;G01S19/29;G01S19/46;H04B7/212;H04J3/06;H04L7/04;(IPC1-7):H04B7/212 |
主分类号 |
G01S19/05 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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